Question

I am getting available memory from below method:

static void print_free_memory () {
float totalSpace = 0.0f;  
NSError *error = nil;  

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);  

NSDictionary *dictionary = [[NSFileManager defaultManager] attributesOfFileSystemForPath:[paths lastObject] error: &error];  

if (dictionary) {  
    NSNumber *fileSystemSizeInBytes = [dictionary objectForKey: NSFileSystemSize];  
    totalSpace = [fileSystemSizeInBytes floatValue];  
    NSLog(@"Total memory:%f",totalSpace);
    freeMemAvailable = [[dictionary objectForKey:NSFileSystemFreeSize] floatValue];
    NSLog(@"Free Memory:%f",freeMemAvailable);
} else {  
    NSLog(@"Error Obtaining File System Info: Domain = %@, Code = %@", [error domain], [error code]);  
}
}

Above method returns = 9139.650391 mb ~ 9.14 GB
AND on Device memory displayed on the Device = 8.4 GB

Approximately, 700 MB difference. Why is it so? Any suggestions.

The path that I used to view the device memory on device is as follows.
Go to :- Settings -> General -> About -> Available

Answer 1

Your calculations are not precise the function return the size in bytes so assume the returned value was 9139650391 you will need to divide it bu (1024*1024*1024) = 1073741824

so 9139650391/1073741824 equals approximately 8.5 GB and not 9.14 GB

about the 100 MB difference, there is still a difference but not as big as 700MB